The present invention relates to a defect inspection device and a defect inspection method capable of inspecting defects such as foreign materials generated on an object to be inspected at the time of manufacturing an LSI or a liquid crystal substrate, etc.
When an LSI or a liquid crystal substrate, etc., are manufactured, as a pattern formed on an object to be processed (for example, a semiconductor wafer), there are a repetitive pattern as represented by a dynamic random access memory (DRAM) part or a random pattern (non-repetitive pattern) represented by logic. In manufacturing the LSI or liquid crystal substrate, etc., when foreign materials are attached to a surface of an object to be processed or defects are generated, it serves as factors causing, for example, an insulation defect, short-circuit, etc., of a wiring. In this case, as a circuit pattern is increasingly fined, there may be a need to discriminate a pattern (non-defective part) formed on the object to be processed and various kinds of fine foreign materials or defects (wiring short, disconnection, pattern thinning, pattern thickening, scratch, non-hole opening, or the like).
However, in order to discriminate the pattern (non-defective part) and various kinds of fine foreign materials or defects, there is a need to change optical conditions including a plurality of illuminating conditions or detecting conditions.
By the way, as the related art of the defect inspection device, JP-A-Hei10(1998)-90192 (Patent Document 1), JP-A-2000-105203 (Patent Document 2), JP-A-2000-155099 (Patent Document 3), JP-A-2003-17536 (Patent Document 4), JP-A-2005-283190 (Patent Document 5), and JP-A-2007-192759 (Patent Document 6) have been known.
In other words, Patent Document 1 discloses an optical inspection device for a sample including a dark-field illumination system and a bright-field illumination system alternately irradiating the same point of a first pattern, a dark-field image detector detecting a reflected image of the first pattern in a dark field, and a bright-field image detector detecting a reflected image of the first pattern in a bright field.
Further, Patent Document 2 discloses a defect inspection device including an illumination optical system for illuminating a slit-type beam to a substrate to be inspected from a plurality of different azimuth directions by switching a light path and a detecting optical system receiving reflected, scattered light provided from defects such as foreign materials, existing on the lighted substrate to be inspected by using an image sensor, converting it into a signal, and detecting the signal.
Further, Patent Document 3 discloses a high-resolution device for observation of a sample surface including an illumination optical system performing polarization lighting on a sample, a polarization optical component more efficiently transmitting polarization-rotated higher-order diffracted light in a sample than zero-order light, and a detecting optical system imaging an image of the sample on a photoelectric transformation device by light transmitting the polarization optical component or reflected therefrom.
Further, Patent Document 4 discloses a pattern inspection device including a floodlight optical system irradiating laser light having wavelength different from each other on a surface of an object to be inspected at different incident angles, a condenser optical system shielding reflected light from the surface of the object to be inspected using a spatial filter and receiving scattered light transmitting the spatial filter, a second dichroic mirror that splits the scattered light condensed in the condenser optical system into different wavelengths, two CCD cameras each receiving and imaging the scattered light that are wavelength-split in the second dichroic mirror, and an image processing unit processing the imaging output of the CCD cameras to determine whether there are defects.
Further, Patent Document 5 discloses defect inspection device including an illumination optical system having a plurality of irradiation units irradiating illuminated light flux emitted from a lighting light source to a surface of a sample from a plurality of azimuth directions different from each other and a light path switching unit switching the illuminated light flux, a vertical direction detecting optical system receiving an optical image scattered in a normal direction among reflected, scattered light from the surface of the sample and converting it into an image signal, an oblique direction detecting optical system receiving an optical image scattered in an oblique direction among reflected, scattered light from the surface of the sample and converting it into an image signal, and an image signal processing unit processing the image signal obtained from both detecting optical systems to detect defects.
In addition, Cited Reference 6 discloses a defect detection device including an irradiation optical system irradiating first and second slit-type beams to a substrate to be inspected from both sides at an inclined angle from the predetermined inclined direction on a plane, a detecting optical system condensing reflected, scattered light from defects existing on the irradiated substrate to be inspected and converting and detecting the condensed reflected, scattered light into a light receiving signal by an image sensor, and an image processing unit extracting a signal indicating defect based on the detected signal, as shown in FIG. 5